Class 8 Maths Worksheet: Squares and Square Roots
The method (Pairs make squares): Square: n × n. Quick way: (a + b)² = a² + 2ab + b², e.g. 42² = 1600 + 160 + 4. Square root: the number that times itself gives the square; a square ending in 4 has a root ending in 2 or 8. Make a perfect square: break into primes; multiply (or divide) by the prime left without a partner. 1 + 3 + 5 + … (n odd numbers) = n². Between n² and (n + 1)² there are 2n whole numbers.
NameDateTime takenScore ___ / 40
- 1.What is √900? =
- 2.What is √3025? =
- 3.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
- 4.What is the smallest whole number by which 45 must be multiplied to get a perfect square?
- 5.What is the sum of the first 13 odd numbers (1 + 3 + 5 + …)?
- 6.A square garden has an area of 25 square m. How long is each side (in m)?
- 7.What is √2809? =
- 8.What is √9801? =
- 9.What is √6400? =
- 10.What is the smallest whole number by which 24 must be divided to get a perfect square?
- 11.A square garden has an area of 729 square m. How long is each side (in m)?
- 12.What is √1024? =
- 13.What is the smallest whole number by which 128 must be multiplied to get a perfect square?
- 14.How many whole numbers lie between 37² and 38²?
- 15.How many whole numbers lie between 42² and 43²?
- 16.A square garden has an area of 1521 square m. How long is each side (in m)?
- 17.Which of these is a perfect square? (a) 1156 (b) 1218 (c) 1161
- 18.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
- 19.A square garden has an area of 841 square m. How long is each side (in m)?
- 20.Which of these is a perfect square? (a) 938 (b) 900 (c) 903
- 21.How many whole numbers lie between 39² and 40²?
- 22.How many whole numbers lie between 10² and 11²?
- 23.What is the smallest whole number by which 162 must be multiplied to get a perfect square?
- 24.What is 92²? =
- 25.What is 72²? =
- 26.What is the smallest whole number by which 240 must be multiplied to get a perfect square?
- 27.What is the smallest whole number by which 150 must be multiplied to get a perfect square?
- 28.What is 35²? =
- 29.What is √324? =
- 30.Which of these is a perfect square? (a) 160 (b) 144 (c) 150
- 31.What is 16²? =
- 32.What is the sum of the first 22 odd numbers (1 + 3 + 5 + …)?
- 33.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
- 34.What is the smallest whole number by which 63 must be divided to get a perfect square?
- 35.What is the smallest whole number by which 52 must be divided to get a perfect square?
- 36.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
- 37.What is √289? =
- 38.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
- 39.What is √225? =
- 40.Which of these is a perfect square? (a) 729 (b) 743 (c) 741
Answer key
- 30
- 55
- 121
- 5
- 169
- 5
- 53
- 99
- 80
- 6
- 27
- 32
- 2
- 74
- 84
- 39
- 1156
- 25
- 29
- 900
- 78
- 20
- 2
- 8464
- 5184
- 15
- 6
- 1225
- 18
- 144
- 256
- 484
- 144
- 7
- 13
- 36
- 17
- 81
- 15
- 729
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